This invention relates to a powdered hair dye, and more particularly to a powdered hair dye which can dye a deep color with an advantage of possessing high stability for longer shelf life.
Because the powdered hair dye has many advantages compared with the liquid type, and it would become more widely used in the future. For the users, the powdered type is light weight, easily carried and economical because it is simple to apportion. For the manufacturer, it is easy to control manufacturing and transport.
Two types of powdered hair dyes are generally known. One is a so-called one-component type, that is, a mixture of a powdered oxidation dye and a powdered oxidizing agent packaged together. The other is a so-called two-component type, that is, a powdered oxidation dye and a powdered oxidizing agent separately packaged. The two-component type of which only the oxidation dye is powdered is also available. In any case, the oxidation dye and the oxidizing agent of the powdered hair dyes are mixed just prior to their use to prepare a tinting mixture. Thus, each component of the hair dye has to be stably stored without deterioration until being prepared as the tinting mixture.
When the oxidation dye or a dye component is stored in a powdery state for a long time, however, it tends to be deteriorated by the effects of moisture. Especially, the tendency is remarkable if the dye component includes both a primary intermediate and a coupler. Furthermore, in the one-component type, since the oxidizing agent acts on the dye components during storage, they are apt to be deteriorated.
Even a part of the dye component is deteriorated during storage, it is hard to achieve a desired and fast color.